As you know, News Manager is currently single-language but (since 2.4.0) it works with a I18N multilanguage site: you see the same posts on any language, but at least links in news pages are correctly generated (they don't take you to a page with a different language). However, texts like "Published on", "Older posts", etc. are always rendered in the language selected for the news page.

Here's a tip to translate those messages.
Let's suppose you have a default language, and English as secondary one.

Insert this code in your theme's functions.php file (create it if your theme hasn´t one, with <?php as first line):